WWDC, Qt, Carbon, 64-bit, and other buzzwords

I had the privilege of attending Apple's World Wide Developer Conference (WWDC) again this year. This is Apple's annual developer get-together in San Francisco where you can find out about Apple's future plans for Mac OS X, chat with fellow developers, and avail yourself of all the Apple engineers on-site. This was my fourth year there and I think I've gotten the hang of it. This year, however, I (and Trolltech) was in for a nasty surprise.

The previous year, Apple announced what its plans were for Mac OS X 10.5 (or Leopard). One of the new features was that Leopard was going to be 64-bit the entire way through. People keeping score at home should note that the C and C++ libraries were 64-bit in Tiger, but none of the GUI libraries like Carbon or Cocoa. Naturally, we knew that there were lots of people who use Qt to write scientific, visualization, and video applications so it seemed like a good idea to make sure that when Leopard was going to be released in "Spring 2007" Qt was there to run in 64-bit. We were in pretty fair shape, having already been on the new Carbon technologies introduced in 10.2, but there were still some things that had to be fixed up, and we had to modify the build system, but that's doable. There were also many bugs in the 64-bit Carbon that we filed bugs against the ones we could get reproducible test cases for. At the end, Qt 4.3.0 was released with the ability to build on Leopard in 32-bit and 64-bit. If you felt plucky enough you could build it all "universal" and have a truly fat binary with versions for PPC, i386, PPC64, and x86_64. This would have been even more impressive, if there was a Leopard that was publicly available so people could take advantage of it.

So, here it was June 2007, we had released Qt 4.3.0, but Apple had delayed Leopard to October. Then, at WWDC, Apple announced that they would not be including HIView and Carbon windows, and other GUI parts of Carbon in 64-bit in their final version of Leopard. This basically contradicts what they said the previous year and makes a fair bit of the work that we did for 64-bit in Qt useless—leaving Qt with a hole for 64-bit support on Mac OS X.

Now, getting news like this hurts on several levels. First, there's the personal level where there's the work you've put in, re-writing classes, adding all the version branches to make things work (writing an #ifdef 64-bit, 10.4, and 10.3 is a interesting exercise), and getting the build system to work. Then there's the fact that there's lots of people who use your library to write amazing applications (I got to see some at WWDC and they were impressive). What can you do for them? Needless to say, it wasn't the most pleasant information to hear.

The rest of the conference, between attending sessions and talking to Apple engineers, I encountered a lot of Qt developers (either in person or via email). This was really positive. I knew that there were quite a few developers out there using Qt on the Mac, but getting a chance to talk them in person is always great. The big question that most people asked was, “what is Trolltech going to do about 64-bit?” As a developer, I couldn't really give a definitive answer other than, “I would be surprised if we don't have some sort of 64-bit solution.” This seemed to ease the fear for these developers and they also seemed to indicate that they were willing to wait a bit for the solution to materialize. As a developer, I can appreciate that response.

Now that I've been back in Oslo, I've actually had a chance to talk to product management and it seems that we will indeed have that 64-bit solution. The official statement is here. It also includes some Q&A that should cover most concerns.

So, in the future you can expect to see a 64-bit version of Qt using Cocoa under the covers. That is, of course, assuming we still have something like HITheme available to draw our controls. Unfortunately, even now I don't know what that answer will be (hopefully yes). When we know what APIs are actually available to us, we can start actually making some sort of schedule. Right now, it's a bit unnerving. If we do get Carbon back in 64-bit, we are in much better shape of course :)

If you feel strongly about this, please don't hesitate to get ahold of your local Apple contact (whether via WWDR or through the contact information in the link above). We already have, but to Apple, Trolltech is but a pebble in the water, but if all Qt/Mac developers let their voice be heard we are a much stronger force.

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